A Joe’s Crab Shack patron bragged online about not tipping a waitress when the restaurant did not have the condiment he requested. He rudely wrote, “Find sour cream” in the place on the till slip that people usually write the tip. He then posted a picture of the receipt on Facebook. The man’s cousin, Dustin Clark, didn’t think this was very nice and posted a response online stating that he would be returning the following day to pay the $10 bill and give the waitress a $10 tip as well. He did just this and made the girl’s day!

Tip is not mandatory. No reason to get sad if not tipped, or some rude comment is written on the slip. (it wasn't even rude). Apparently, not a very professional waitress. She can't handle the reality.

yes... in the USA, waiters and waitresses usually do not get paid enough to support themselves. there is a gentleman's agreement that the artificially lower prices the customer pays should be reciprocated in a 20% tip or so to the wait staff.

in the end it leads to about the same bill anyway. so... in the USA there is no reason to be cheap and rude towards friendly wait staff.